How to check if datastore value changed?

local dataservice = game:GetService('DataStoreService'):GetDataStore("example")
game.Players.PlayerAdded:connect(function(player)
	

----------------------------------------------------------------
	local ukey = 'id-'..player.userId
	local titanium = Instance.new('IntValue') --- Store titanium
	local resources = Instance.new('Folder',player)
	resources.Name = 'Resources'
	titanium.Parent = resources
	titanium.Name = 'Titanium'
	
	
	local GetSaved = dataservice:GetAsync(ukey)
	if GetSaved then
	
		titanium.Value = GetSaved[1]
	
		
		
		
		if titanium.Value ~= 0 then
			game.Lighting.Items.Titanium:Clone().Parent = player:WaitForChild("PlayerStorage")
			player.PlayerStorage.Titanium.Quantity.Value = titanium.Value
			
		
		end
	
	else
		local NumberForSaving = {titanium.Value}
		dataservice:SetAsync(ukey, NumberForSaving)
		
		
		
	end	
	
	
end)




game.Players.PlayerRemoving:connect(function(player)
	local ukey = 'id-'..player.userId
	local savedtbl = {player.Resources.Titanium.Value}
	dataservice:SetAsync(ukey, savedtbl)
end)

The script above It's my datastore script obviously... what i'm trying to do is when a player who joined the game titanium value does not equal to 0 a part from lighting will be clone to the player instance folder called "resources". so anyone who joined the game as long as their titanium value does not equal to 0 it will clone the part...

THE PROBLEM

If a player is new to the game and of course the player titanium value is 0 because the player hasn't played yet meaning the the part will not be cloned.. since the player titanium value is 0. Now if the player during the game gathered a titanium using a tool inside the tool i have a script which will add a value to the player titanium

Player.Resources.Titanium.Value = Player.Resources.Titanium.Value +5

Like that^, now i want to make it clone the part because the player titanium value is no longer equal to 0 and i want to clone the part only once just like when a player joins the game.

You essentially need an "OnChange" event handler (or perhaps a "SetTitanium" method) that will keep track of this for each player. Since you're creating the titanium IntValue right there, it is easy to add an OnChange to it:

if titanium.Value ~= 0 then
	game.ReplicatedStorage.Items.Titanium:Clone().Parent = player:WaitForChild("PlayerStorage") --note that I've changed Lighting to ReplicatedStorage; you should move your stuff there
	player.PlayerStorage.Titanium.Quantity.Value = titanium.Value
else
	local con --must have this on its own line to reference it in the Changed function
	con = titanium.Changed:connect(function(prop)
		if prop ~= "Value" then return end --This is mainly here because some Roblox properties have multiple names and trigger the Changed event multiple times, but we don't want to SpawnPart more than once.
		if titanium.Value > 0 then
			con:disconnect() --we no longer need to listen to the Changed event
			game.ReplicatedStorage.Items.Titanium:Clone().Parent = player:WaitForChild("PlayerStorage")
		end
	end)
end

As you can see, the idea is simply to keep track of the titanium value until it is non-zero. At that point, the player receives the cloned part. (You might want to put that cloning line into its own function to avoid duplication.)

Note: I do not update the PlayerStorage.Titanium.Quantity.Value in the OnChanged event. If you want that auomatically kept up-to-date, you can add it, but would then need to remove the con:disconnect() part.

The note beside the local con is saying that this wouldn't work:

local con = titanium.Changed:connect(function(prop)
	--con will be nil here, so calling con:disconnect() will create an error
	--This is because, when the function is being created, 'con' doesn't exist. Once the function is created and passed to the 'connect' function, *then* 'con' is created.
end)